Tiltable tray sorting system with adjustable drive means

ABSTRACT

A commodity sorting system has an induction loader unit, a code entry unit, a central control unit, a loading station, a closed loop chain, a closed loop track following the same path as the closed loop chain, and a plurality of carriages riding on the track and having coupling structure fixedly connecting the carriages to the closed loop chain. The carriages each has a tray mounted thereon that is capable of being tilted laterally in either direction at one of the plurality of discharge stations located on opposite sides of the track. Carriage tip-up units are mounted along side of the track at each discharge station and these tilt the trays on the carriages as the carriage approaches the destination discharge station for each commodity package. The tip-up units act in response to a signal sent from the central control unit that initially receives the destination discharge station code indicia of each commodity package that had been inserted into the code entry unit.

United States Patent 1 1 1111 3,881,609 Ellis et al. 1 1 May 6, I975 154] TILTABLE TRAY SORTING SYSTEM WITH 3,765,525 10/1973 Hartwig 198/208 ADJUSTABLE DRIVE MEANS [76] Inventors: Peter H. Ellis, 545 Parkway, Chula Primary Emmmer R0ben Spar Vista Calif 92010; Allen R Assistant ExaminerR. B. Johnson Eastham, 688 Mission Ct., Chula Vista, Calif. 92012; Cecil 57 ABSTRACT Bainbridge, 4475 Dale; Wiley F.

Yip, Tangoemd Ln. both of La A commodity sorting system has an induction loader Mesa, Calif 92041 unit, a code entry unit, a central control unit, a loadmg station, a closed loop cham, a closed loop track Flledi y 1974 following the same path as the closed loop chain, and [2|] App]. No: 473,835 a plurality of carriages riding on the track and having coupling structure fixedly connecting the carriages to the closed loop chain. The carriages each has a tray Cl 214/11 193/208 mounted thereon that is capable of being tilted later- II'IIL Cl. in either direction at one of the plurality of dis- Field of Search 214/1 1 11 charge stations located on opposite sides of the track.

1985308 Carriage tip-up units are mounted along side of the track at each discharge station and these tilt the trays References Cited on the carriages as the carriage approaches the desti- UNITED STATES PATENTS nation discharge station for each commodity package. 2,919,790 l/l960 Winz et 198138 The P- P units act in response to a Signal Sent from 293 434 4 19 0 Muner ct 3| g 93 3 the central control unit that initially receives the desti- 3,I67,192 1/1965 Harrison et al. 214/11 R nation discharge station code indicia of each commod- 3,482,260 12/1965 Gary 214/11 R ity package that had been inserted into the Code 3,49l,903 H1970 Hedrick et al. 2l4/l l R nt unit 3,662,874 5/l972 Muller l98/38 X 3,712,457 1/1973 Pelzer 198/208 9 Claims, 7 Drawing Figures PATENTH MAY 8975 3. 88 1 609 SHEET 10F 3 I TTENTEE RAY 619. 5

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PATENTEDMAY BIBTS 3.881509 SHEET 3 OF 3 TILTABLE TRAY SORTING SYSTEM WITH ADJUSTABLE DRIVE MEANS BACKGROUND OF THE INVENTION The invention relates to a conveyor system and particularly to a commodity sortation system adapted to automatically transport and distribute a series of commodities from one or more sources to predetermined discharge stations.

The sortation and distribution of commodities for subsequent processing in major establishments is relatively expensive and time consuming. The warehouses of many of these major establishments operate on the bulk pickup principle wherein a plurality of different items taken from stock must be sorted and assembled into orders before delivery to a central packaging department. Additionally many shipping departments of mass production industries require automatic sortation and distribution units. Presently there are a number of commodity sortation systems available to the manufacturing and merchandising companies but these lack refined structure to greatly increase their efficiency and also to prevent malfunctions of essential mechanical members.

The type of commodity sortation system to which the invention applies has a carriage that travels around a closed loop track. Trays are mounted upon these carriages and they have a cam member that is actuated to tilt the trays laterally in either direction. Tip-up units positioned along the side of the track have a cam follower that engages the cam member of the carriage as it passes. In the past a problem has existed since the cam follower roller could not maintain full tracking contact across its lateral face with the cam member as it was tilted laterally. This caused increased stresses and wear on the cam follower roller since only corner contact on the roller was maintained with the tilting cam member. Also due to the skew angle present in the tracking geometry, the cam follower roller could be deilected off the outside edge of the cam surface when maximum loads were being conveyed on the tray thus resulting in incomplete unloading of the carriage tray. A further inadequacy resulted from the failure of the tip-up units to have a good positive return assembly to move the tip-up cam follower roller away fast enough to clear the next carriage. An additional problem was the low cylce fatigue failures experienced at the junction of the tip-up lever to the actuator attachment. The failure of the drive motor or parts in the drive unit of prior systems also resulted in excessive down time partly because of the necessity of having to release the tension of the closed loop chain prior to removal of any of the major components of the drive unit for repair or replacement.

It is an object of the invention to produce a more efficient commodity sortation system. It is also an object of the invention to provide an improved cam tracking surface on the cam member of the conveyor carriage unit of a commodity sortation system.

It is also an object of the invention to provide an improved positive return mechanism for the tip-up assem bly unit of a commodity sortation system.

It is a further object of the invention to provide an improved structure for attaching the cam follower roller to the actuator mechanism of the tip-up assembly unit of a commodity sortation unit.

lt is an additional object of the invention to provide an improved structure for connecting a drive unit to the closed loop chain of a commodity sortation system.

SUMMARY OF THE INVENTION The commodity sortation system includes provisions for induction, sortation, and distribution of commodities. It comprises an induction loader unit, a code entry unit, a central control unit, a loading station, a closed loop chain, a closed loop chain, a closed loop track following the same path as said closed loop chain, and a plurality of carriages riding on said track and having coupling structure fixed connecting the carriages to the closed loop chain. Motive power to transport the carriages along the closed loop track is provided by the drive unit which rotates the main sprocket engaging the closed loop chain.

The improved drive unit of the invention offers superior operating characteristics plus rapid field replacement in the event of component failure. It embodies a solid-state electronic controlled, direct current electric drive motor coupled to a gear reduction unit all mounted on a common skid platform in such a manner to permit rapid uncoupling and removal of this module from the sortation system for maintenance or replacement without disturbing the main drive sprocket or tension on the closed loop chain. Other features to facilitate maintenance or replacement of critical items are also embodied in the arrangement of the drive unit. The drive unit mechanical brake is located on the end of the drive motor opposite from the gear reduction box to provide ease of accessibility. By acting on the motor armature shaft, the size of the mechanical brake is minimized. The drive motor tachometer is mounted at the end of the mechanical brake thereby providing maximum accessibility. A number of superior operating characteristics are provided by the utilization of a solid-state silicon controlled rectifier motor controller to operate the direct current sorter drive motor. This combination provides a fully adjustable range of selected motor operating speeds up to the rated motor speed with rated motor torque developed at all speeds. Rates of drive motor acceleration and deceleration can also be varied over a wide range.

The improved mechanism for laterally tilting the trays on the carriages provides new structure on the carriage cam member and also in the tip-up unit. As to the cam member, its cam surface is comprised of the forward unlatching portion and the rear tipping portion. The forward portion has a substantially linear surface that is canted laterally along its longitudinal axis. The rear portion is non-linear and has a warped concave surface with the major warpage occurring at its forward edge with the warpage growing lesser along the length of the rearward portion. By virtue of the canted forward portion and the warped rear portion of the cam member, contact is provided across the full width of the cam follower wheel for the entire length of the cam engagement. This full contact imparts improved tracking of the cam follower wheel along the cam surface and assures satisfactory tipping with the heaviest conveyed load located in the most adverse position on the tray surface. Eliminated are the increased stresses and wear on the cam follower roller and the possibility of the cam follower roller being deflected off the outside edge of the cam surface. The operating characteristics of the tip-up assembly have been improved by providing structure for powering the tip-up arm to its return position so that the next carriage will clear the top of the cam follower roller. The self-aligning bearing at the attachment of the actuator to the tip-up arm also improves the operation and increases the life of the connection at the junction of the two members.

DESCRIPTION OF THE DRAWINGS FIG. 1 is a schematic drawing of the commodity sorting system,

FIG. 2 is a side elevation view of the commodity sorting system drive unit illustrating the sprocket geat housing with portions broken away,

HO. 3 is a partial end elevation view of the commodity sorting system drive unit,

FIG. 4 is a partial front elevation view of the tip-up assembly unit,

FIG. 5 is a partial side elevation view of one of the conveyor carriage units,

FlG. 6 is a front elevation view of the conveyor carriage just as the roller on the tip-up assembly initially contacts the cam lever arm, and

FIG. 7 is a front elevation view of the conveyor carriage illustrating how the tip-up assembly laterally tilts the tray mounted on top of the conveyor carriage.

DESCRlPTlON OF THE PREFERRED EMBODIMENT Referring to FIG. 1, the commodity sorting system is generally designated numeral 10. It includes a conveyor unit 12, code entry units 14, a central control unit 15, induction loader units 16, a closed loop chain 18, a track 19, carriage members 20, a drive unit 22, and discharge chutes 24. In operation the commodities to be sorted and distributed are all brought to the system on the conveyor unit 12. At this point the individual commodities are placed one at a time on an induction loader unit by a first operator. A second operator reads the destination code marked on the commodity and types it into the code entry unit 14. The commodities are then transported forward to the loading station L where they are automatically loaded onto the top surface of a tray mounted on one of the carriages 20. When the destination code was typed into code entry unit 14 this information was transmitted to central control unit 15 where it was recorded on its memory. The central control unit is programed to know what tray each commodity is placed on, the speed of travel of the carriage on the track, and destination of each commodity which was typed into the code entry unit. As each carriage approaches the predetermined destination of its commodity, an electrical signal is sent out to actuate the tip-up assembly 100 at the proper discharge station R. The cam follower roller 125 of the tip-up assembly 100 is then projected upwardly into engagement with cam member 180 on the carriage member 20. This causes tray 11 to be tilted laterally at the proper discharge station R with the commodity then sliding off tray 11 onto a discharge chute 24. The structure of the carriages and the tip-up assemblies 100 will be described later.

The drive unit for the commodity sorting system is best described by referring to FIGS. 2 and 3. In the particular embodiment illustrated, track 19 is elevated above the floor and the drive unit is supported upon base that is anchored to the floor. A skid 32 is positioned upon sliding pads 36 and 37 attached to the upper surface of base 30. A longitudinally extending clamp 40 is attached to the upper surface of base 30 ad jacent sliding pad 37. Clamp 40 forms a channel along which the flange of skid 32 may be longitudinally slid. Adjacent sliding pad 36, a threaded plate is attached to the upper surface of base 30 and a bolt is screwed therethrough for securing skid 32 in position. The above described structure is utilized for setting the proper tension on closed loop chain 18. The manner for doing this is to place the base of a jack against jack pad 31 with its top surface against a horizontal wall of skid pad 32. The jack is then actuated till the desired tension is placed upon chain 18. Bolt 42 is then fastened firmly in the manner of a set screw against the side of skid 32 to secure it longitudinally in place.

An auxiliary structure for maintaining the proper tension on chain 18 comprises a pair of take-up screws 78 and nuts 80. These take-up screws are located on the lateral sides of skid 32 with their rear end being supported by braces and post 77. The forward end of take-up screws 78 pass through apertures in transverse beam 78 that is supported by legs 72 and 73 attached to the top of skid 32. By tightening nuts after skid 72 has been secured to base 30, the bending moment on shaft 64 that extends upwardly through means 78 is minimized.

Once the proper tension has been placed on chain 18 it is not necessary to release that tension in order to remove any of the drive unit components for servicing or replacement. The reason for this is that all of these components are mounted on a skid 34 that is supported on sliding pads 38 and 39 on the top surface of skid 32. Threaded bracket plates 43 and 45 are secured to the top of skid 32 and by proper adjustment of bolts 44 and 46 both the longitudinal and transverse movement of skid 34 with respect to skid 32 can be obtained. This allows for ease in aligning shaft 60 with shaft 64 that turns the main sprocket that drives chain 18. Any time that it is necessary to remove the drive unit all that need be done is for coupling 62 to be loosened thereby freeing all of the drive unit from shaft 60 downwardly.

Mounted atop skid 34 is electric motor 52 whose electrical power is supplied through cable 53. Brake 54 is secured to one end of the shaft of motor 52 with tachometer 55 also mounted on that same end of the shaft. Shaft 56 extends from the other side of motor 52 and through coupling 57 it is attached to shaft 58 of gear box 50.

Referring to FIG. 2, chain 18 which is driven by shaft 64 is illustrated passing through the bottom of housing 84. The individual carriages 20 are seen to ride on rail 19 and they are secured to chain 18 by a bolt and nut 92. lntermediately locked on bolt 90 in the carriage is a roller 94 that functions to keep the carriage base from housing 84 as it passes around the curved loop.

The carriages are shown in enlarged view in FIGS. 5 through 7 and will now be described. Basically they comprise a body having a longitudinally extending frame member 162 with upstanding support members 164 and 165 located fore and aft. A pair of axles 151 pass through frame member 162 and have wheels 150 secured thereon for rolling movement. A tray member 11 is secured to a tray support member that is pivotally attached to the fore and aft upstanding support members by shafts 184 and 186. It is this structure that allows the trays to be tilted laterally in either direction. A carriage cam member is pivotally attached to the underside of the tray supportmernber by shafts 182 allowing the forward portion of the cam member 180 to pivot upwardly about a horizontal axis that is substantially perpendicular to the longitudinal axis of the carriage. Spring 90 normally biases the cam member into a downward locked position. Locking means 170 and 172 are secured respectively to the support member 165 and cam member 180. With spring member 190 extended in its elongated position the tray support member is prevented from tilting laterally. The cam surface of cam member 180 is comprised of an unlatching surface 192 and a tilting surface 194. The manner in which these cam surfaces relate to the tip-up unit will be described later.

The tip-up unit 100 is illustrated in FIG. 4. It is attached to the underside of the track 19 by bracket 104 that extends transversely under the track and has upstanding arms 106 on either side. The actuator assembly 110 is attached to arm 106 by support bracket 1 12. The actuated assembly consists of an air cylinder motor 114 having a piston rod 116 extending upwardly therefrom. A self-aligning bearing 118 is attached to the tip of piston rod 116 and is in turn secured between legs 12] and 122 of tip-up arm 120. Fingers 128 and 129 of the tip-up arm have a shaft 126 connected between them with a cam follower roller 125 mounted thereon. The tip-up unit 100 is actuated in response to an electrical signal from control unit 15. The electrical signal is transmitted through cable 136 to actuate a solenoid that operates four-way valve 134. Air lines 137 and 138 are connected to the four-way valve 134 and release air through air lines 131 and 132 to raise and lower cam follower roller 125 in response to the proper signal from central control unit 15, thus the cam follower roller is positively driven upwardly and positively retracted. Cam follower roller 125 is illustrated in its tipped up position in FIGS. 6 and 7 to show how roller 125 contacts unlatching surface 192 for unlatching the locking means of the carrier. Thereafter the roller follows the non-linear warped concave surface of the tipup portion 194 of cam member 182 to tilt the tray and unload the commodity. The major warpage occurs at the forward edge of tip-up surface 194 with the warpage growing lesser along the length of the rearward portion of the cam member. As can be seen in the drawings the cam follower roller 125 can thus maintain full lateral width contact with the cam member throughout the tipping up and tilting operation for unloading the carriage trays at the desired receiving stations.

Having thus described the invention, what is claimed as new and useful and desired to be secured by US. Letters Patent is:

1. A commodity sorting system comprising:

a closed loop chain means,

a closed loop track following the same path as that of said closed loop chain means,

a plurality of carriages riding on said closed loop track and having means connecting said carriages to said closed loop chain means whereby travel of said chain means about its loop causes said carriages to travel around said closed loop track, said carriages each having a tray mounted thereon and having means to allow said trays to be laterally tiltable in either direction,

a first vertical drive shaft, means for driving said chain means about its loop comprising a sprocket gear horizontally oriented on said first vertical drive shaft, first skid means, bearing means, said first vertical drive shaft being rotatably supported in said bearing means that are in turn fixedly supported above said first skid means, a motor, gear drive means, second skid means slidably mounted on said first skid means, said motor being coupled to said gear drive means, means mounting said gear drive means on said second skid, a second vertical drive shaft extending upwardly from said gear drive means in axial alignment with said first vertical drive shaft and coupling means to secure the two vertical shafts together to transmit torque from said motor to said first vertical drive shaft,

base means having sliding pads upon which said first skid means is mounted, said base means having means to adjust the tension in said closed loop chain means,

at least one loading station and a plurality of discharge stations,

carriage tip-up means positioned at each discharge station,

code entry unit means into which destination discharge station code indicia from each commodity package is inserted just prior to its being loaded onto one of said carriage trays at said loading station,

central control unit means for receiving the information fed into the code entry unit means to establish a memory circuit to control the discharge of the commodity package at a destination discharge station by sending an electrical signal to said carriage tip-up means positioned at said discharge station causing it to be actuated as the carriage tray approaches the destination discharge station.

2. A commodity sorting system as recited in claim 1 wherein said means to adjust tension in said closed loop chain comprises a primary adjustment means and a secondary adjustment means, said primary means comprising a jack pad against which a jack may be positioned to act against said first skid means and clamp means for fixedly securing said first skid means in locked position on said base means.

3. A commodity sorting system as recited in claim 2 wherein said secondary adjustment means comprises threaded take up screws that have one of their ends attached to frame superstructure extending upwardly from the rear of said base with their other ends attached to a beam that fixedly supports the bearing means in which said first vertical drive shaft is journaled.

4. A commodity sorting system as recited in claim 3 further comprising clamp means for fixedly securing said second skid means in locked position on said first skid means to insure proper alignment between said first and second vertical drive shafts.

S. A commodity sorting system as recited in claim I wherein said carriage tip-up means comprises: an actuator assembly having a piston rod for reciprocating motion, a self-aligning bearing attached to the free end of said piston rod and a tip-up ann attached to said selfaligning bearing, the free end of the tip-up arm having a cam follower roller mounted therein.

6. A commodity sorting system as recited in claim 5 wherein means are connected to said actuator assembly to power the tip-up arm to the tip position and to power the tip-up arm to the return position, said means comprising a four-way valve that is actuated in response to an electrical signal from said central control unit means.

7. A commodity sorting system as recited in claim I wherein said means to allow said trays to be laterally tiltable in either direction comprises a carriage body having fore and aft upstanding support members, a tray support member pivotally attached to said fore and aft upstanding support members, a carriage cam member pivotally attached to the underside of said tray support member allowing its forward portion to pivot upwardly about a horizontal axis that is substantially perpendicular to the longitudinal axis of the carriage. locking means attached to the underside of said cam member and said fore upstanding support member, said cam member having substantially identical cam surfaces along its lower lateral edges against which the cam follower roller of the carriage tip-up means rolls, each cam surface having a forward portion that functions to unlatch the tray from its horizontal locked position and a rear portion that functions to lateral tilt said tray, said forward portion having a substantially linear surface that is canted laterally along its longitudinal axis, said rear portion being non-linear and having a warped concave surface with the major warpage occurring at its forward edge with the warpage growing lesser along the length of the rearward position.

8. A commodity sorting system as recited in claim 1 further comprising induction loader means for automatically placing commodity packages on said carriage trays at said loading station.

9. A commodity sorting system as recited in claim 1 including discharge chutes located on opposite sides of said track at some of said discharge stations.

l l I: 

1. A commodity sorting system comprising: a closed loop chain means, a closed loop track following the same path as that of said closed loop chain means, a plurality of carriages riding on said closed loop track and having means connecting said carriages to said closed loop chain means whereby travel of said chain means about its loop causes said carriages to travel around said closed loop track, said carriages each having a tray mounted thereon and having means to allow said trays to be laterally tiltable in either direction, a first vertical drive shaft, means for driving said chain means about its loop comprising a sprocket gear horizontally oriented on said first vertical drive shaft, first skid means, bearing means, said first vertical drive shaft being rotatably supported in said bearing means that are in turn fixedly supported above said first skid means, a motor, gear drive means, second skid means slidably mounted on said first skid means, said motor being coupled to said gear drive means, means mounting said gear drive means on said second skid, a second vertical drive shaft extending upwardly from said gear drive means in axial alignment with said first vertical drive shaft and coupling means to secure the two vertical shafts together to transmit torque from said motor to said first vertical drive shaft, base means having sliding pads upon which said first skid means is mounted, said base means having means to adjust the tension in said closed loop chain means, at least one loading station and a plurality of discharge stations, carriage tip-up means positioned at each discharge station, code entry unit means into which destination discharge station code indicia from each commodity package is inserted just prior to its being loaded onto one of said carriage trays at said loading station, central control unit means for receiving the informatIon fed into the code entry unit means to establish a memory circuit to control the discharge of the commodity package at a destination discharge station by sending an electrical signal to said carriage tip-up means positioned at said discharge station causing it to be actuated as the carriage tray approaches the destination discharge station.
 2. A commodity sorting system as recited in claim 1 wherein said means to adjust tension in said closed loop chain comprises a primary adjustment means and a secondary adjustment means, said primary means comprising a jack pad against which a jack may be positioned to act against said first skid means and clamp means for fixedly securing said first skid means in locked position on said base means.
 3. A commodity sorting system as recited in claim 2 wherein said secondary adjustment means comprises threaded take up screws that have one of their ends attached to frame superstructure extending upwardly from the rear of said base with their other ends attached to a beam that fixedly supports the bearing means in which said first vertical drive shaft is journaled.
 4. A commodity sorting system as recited in claim 3 further comprising clamp means for fixedly securing said second skid means in locked position on said first skid means to insure proper alignment between said first and second vertical drive shafts.
 5. A commodity sorting system as recited in claim 1 wherein said carriage tip-up means comprises: an actuator assembly having a piston rod for reciprocating motion, a self-aligning bearing attached to the free end of said piston rod and a tip-up arm attached to said self-aligning bearing, the free end of the tip-up arm having a cam follower roller mounted therein.
 6. A commodity sorting system as recited in claim 5 wherein means are connected to said actuator assembly to power the tip-up arm to the tip position and to power the tip-up arm to the return position, said means comprising a four-way valve that is actuated in response to an electrical signal from said central control unit means.
 7. A commodity sorting system as recited in claim 1 wherein said means to allow said trays to be laterally tiltable in either direction comprises a carriage body having fore and aft upstanding support members, a tray support member pivotally attached to said fore and aft upstanding support members, a carriage cam member pivotally attached to the underside of said tray support member allowing its forward portion to pivot upwardly about a horizontal axis that is substantially perpendicular to the longitudinal axis of the carriage, locking means attached to the underside of said cam member and said fore upstanding support member, said cam member having substantially identical cam surfaces along its lower lateral edges against which the cam follower roller of the carriage tip-up means rolls, each cam surface having a forward portion that functions to unlatch the tray from its horizontal locked position and a rear portion that functions to lateral tilt said tray, said forward portion having a substantially linear surface that is canted laterally along its longitudinal axis, said rear portion being non-linear and having a warped concave surface with the major warpage occurring at its forward edge with the warpage growing lesser along the length of the rearward position.
 8. A commodity sorting system as recited in claim 1 further comprising induction loader means for automatically placing commodity packages on said carriage trays at said loading station.
 9. A commodity sorting system as recited in claim 1 including discharge chutes located on opposite sides of said track at some of said discharge stations. 